1. Field of the Invention
The present invention relates to road spikes with improved characteristics and methods of deployment, and in particular to road spikes made of long fiber reinforced thermoplastics that, when deployed, are geometrically positioned to puncture or disable a tire.
2. Description of the Related Art
The problems associated with stopping the escape of a vehicle in police and military applications are well known. It is desirable to cause rapid stopping of the vehicle by puncturing one or more tires, and then allowing the air to escape without plugging the hole. There are numerous devices that are designed to accomplish these tasks. Some examples are:
U.S. Pat. No. 2,346,713 to Walker is titled Caltrop. This patent teaches a body having four hollow arms equally spaced about a body. When three of the arms are in contact with a horizontal surface, the fourth arm is vertically oriented.
U.S. Pat. No. 2,912,229 to Persgard is titled Vehicle Impeding Device. This patent illustrates the use of spikes that are releasably received within a base, and as such, can be picked up by a tire.
U.S. Pat. No. 5,328,292 to Williams is titled Traffic Barrier Chain. This patent shows a barrier chain having splines, wherein ½ of the splines face the direction of the traffic flow at an angle of 45 degrees. The splines, however, do not appear to be removable from the chain. Also, any deviation from having the chain deployed perpendicular to the flow of traffic will result in deviation from the illustrated puncture angle.
U.S. Pat. No. 5,921,703 to Becker et al. is titled Caltrop. This patent illustrates a rigid caltrop structure that is formed from two metallic members which abut each other and are welded together. Pairs of adjacent corners of sides of triangular portions create penetration points. When three of the penetration points rest on a horizontal surface, the fourth penetration point projects upwards. The angle of penetration point projection is dependent upon the rotational angle of the caltrop relative the road surface.
U.S. Pat. No. 6,312,189 to Marphetia is titled Vehicle Tire Puncturing and Deflating Spike and Assembly Therefor. This patent shows a configuration of a metal spike.
U.S. Pat. No. 7,210,875 to Christle et al. is titled Entrapment Snare for the Termination of Vehicle Pursuits. This patent illustrates the use of two small but heavy weights connected by a flexible cable covered with spikes. FIG. 12 of this patent illustrates a spike design wherein all of the spikes are within a singular plane. Also, the spikes do not appear to be removable from the chain.
None of the existing products, including those illustrated in the above-mentioned patents teach, show or suggest spike assembly containing multiple spikes that can be removably attached to a deployment string.
Further, it is the industry standard to use metal spikes. This is because plastic is regarded as either too brittle (subject to shatter) or too flexible (incapable of puncture) to be used as road spikes. Yet metal spikes can be expensive, heavy and may require corrosion prevention protection. Hence, an engineered solution using plastics is desirable, both as replacement spikes in existing systems and as integrated devices.
Still further, none of the existing products, including those illustrated in the above-mentioned patents teach, show or suggest a configuration aligns at least one spike angled vertically divergent towards oncoming traffic regardless of device rotational orientation.
Related, none of the existing products, including those illustrated in the above-mentioned patents teach, show or suggest a six point configuration wherein the device is automatically self-leveling and self-centering on three spikes and having three remaining spikes project upwards with at least one spike being angled vertically divergent towards oncoming traffic regardless of the device rotational orientation.
Thus, there exists a need for road spikes with improved characteristics that solves these and other problems.